Scientists are already building an interstellar Schrödinger gun. And they don't even know it. Super-sensitive neutrino detectors are the death of reason, I tell you.
This is the Great Filter, isn't it? Civilizations get just smart enough to disrupt cognition throughout the galaxy.
Hey, it looks like they're making beams of antineutrinos. What happens when a beam of antineutrinos intersects with a beam of neutrinos? Do they annihilate, and release energy? That'd be neat, since they don't interact with anything on the way there. It'd be a way to deliver energy to an arbitrary point in space.